1980 CB650 Project
- Thread starter Scott84
- Start date
620dark
You can always get it running with time or money.
It's good to see another CB650 project 
Some folks have had success repotting the spark units with JB Weld epoxy. I gather that the problem isn't always the spark units so much as it is the epoxy they are filled with. Doesn't cost much to try.
If that doesn't work for you (and if the bike runs, the spark units are probably ok), the units are common to CB750s, Goldwings, and all manner of late '70s / '80s Hondas, so they should be pretty easy to find. I didn't have much luck getting my GM HEI conversion going, but I think I got crap HEI modules, so if you do go that way, don't buy the cheapest HEI modules like I did.
Good luck with the bike!
Some folks have had success repotting the spark units with JB Weld epoxy. I gather that the problem isn't always the spark units so much as it is the epoxy they are filled with. Doesn't cost much to try.
If that doesn't work for you (and if the bike runs, the spark units are probably ok), the units are common to CB750s, Goldwings, and all manner of late '70s / '80s Hondas, so they should be pretty easy to find. I didn't have much luck getting my GM HEI conversion going, but I think I got crap HEI modules, so if you do go that way, don't buy the cheapest HEI modules like I did.
Good luck with the bike!
Thanks for the tip I just about ordered the cheapest HEI modules I could find and I haven't run the bike for more than a min so i'm not sure if the igniters will give me hell or not if they work fine ill use jb weld if not i'll do the HEI. Also has anyone ran smaller speedo and tach from like a xl250? Sorry for crappy cell pics
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620dark
You can always get it running with time or money.
Those mechanical carbs can be a real bitch to get running right. I ended up buying a micro drill bit set and ran the proper diameter drill bits through the slow and main jets to clear out all the crud. Also make sure you're using the stock air box unless you are willing to rejet the bike and tune the hell out of it.
Thanks for the advice the bike already has a 4 into 1 exhaust so I was thinking I would get pods and run the jetting like Rusty knuckles CB650 that has a 4 into 1 and pods he has his jetting on his build up page. His bike is a 1979 and mine is an 80' do you think I would have a problem going to his setup with out to much of a 'problem plus I'm already doing major carb work because the air screws are seized up and the head snapped off.....
620dark
You can always get it running with time or money.
Jetting should be pretty close to the Rusty Knuckles bike - here's another reference link:
http://www.chinonthetank.com/2010/08/cb650-pod-filters/
The Cliff's notes are:
120 main jet (stock is 92)
42 slow jet (stock is 35)
mixture screws set to 1.75 turns out
float height set to stock measurement
Good luck getting the air screws out - that sounds like a real pain in the ass!
http://www.chinonthetank.com/2010/08/cb650-pod-filters/
The Cliff's notes are:
120 main jet (stock is 92)
42 slow jet (stock is 35)
mixture screws set to 1.75 turns out
float height set to stock measurement
Good luck getting the air screws out - that sounds like a real pain in the ass!
Here is the bike that I get the pleasure of riding. A 1985 yamaha Virago 1000 with 2300 origanal miles that my grandpa has had since new. This bike still has the origanal dunlaps! I also added pics of the head I cut into the air pilot screw.
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Well I've been slowly working on the old CB650 here are the latest pics with new tires some more polishing and my favorites of the rust removal by way of electrolysis. The picture is of the anode that collected the rust that is one of 3 that I made. 8)
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Well I guess its time I've got around to getting this updated. I fought and fought the original carbs just to get the bike running, so I decided that I needed to try these 1995 cbr 600 carbs that I found on ebay for 35 bucks. I cleaned the rust out of the bowls and jets and fitted them on my bike with some radiator hose I bought from napa. I put some gas in the bowls and the bike fired right up with some help from the choke! After I got the cob webs blown out the bike ran awesome and started really easy after that and the carbs leak gas out of the back of the carb. Im not to sure how im going to fix that yet im going to try to plug the hole and see if it runs. I put about 200 miles on the bike and i enjoyed every bit of it, but the bike smoked quite a lot so I bought an athena top end kit and rings. The tear down went really easy and great. I found out why it was smoking too the oil scraping rings on 1 and 4 were broken and was missing half of the ring. I think the top end was rebuilt and the rings weren't pinched in right when the jugs went back on and they broke then. I dont have the bike back together yet but it should be going back together tonight.
